From c9addba5cc770d2d231b34f6739f32c6be8690f1 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 15 Apr 2024 21:37:10 +0200 Subject: Adding upstream version 2.12.0. Signed-off-by: Daniel Baumann --- src/ult_src.c | 452 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 452 insertions(+) create mode 100644 src/ult_src.c (limited to 'src/ult_src.c') diff --git a/src/ult_src.c b/src/ult_src.c new file mode 100644 index 0000000..c21aa51 --- /dev/null +++ b/src/ult_src.c @@ -0,0 +1,452 @@ +/* + * ult_src.c: Find the ultimate source of a page + * + * Copyright (C) 1994, 1995 Graeme W. Wilford. (Wilf.) + * Copyright (C) 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011, + * 2012 Colin Watson. + * + * This file is part of man-db. + * + * man-db is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * man-db is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with man-db; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * code to seek out the original (ultimate) source man file for + * any specified man file. Soft and hard links and .so inclusions + * are traced. Use: reduce amount of cat files to a minimum. + * + * Mon May 2 11:14:28 BST 1994 Wilf. (G.Wilford@ee.surrey.ac.uk) + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif /* HAVE_CONFIG_H */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "canonicalize.h" +#include "dirname.h" +#include "error.h" +#include "gl_array_list.h" +#include "gl_hash_map.h" +#include "gl_xlist.h" +#include "gl_xmap.h" +#include "xalloc.h" +#include "xstrndup.h" +#include "xvasprintf.h" + +#include "gettext.h" +#define _(String) gettext (String) + +#include "manconfig.h" + +#include "compression.h" +#include "debug.h" +#include "glcontainers.h" + +#include "decompress.h" +#include "ult_src.h" + +void gripe_canonicalize_failed (const char *path) +{ + if (quiet < 2) { + if (errno == ENOENT) + error (0, 0, _("warning: %s is a dangling symlink"), + path); + else + error (0, errno, _("can't resolve %s"), path); + } +} + +/* Find minimum value hard link filename for given file and inode. + * Returns a newly allocated string. + */ +static char *ult_hardlink (const char *fullpath, ino_t inode) +{ + DIR *mdir; + struct dirent *manlist; + char *base, *dir, *ret; + const char *slash; + + slash = strrchr (fullpath, '/'); + assert (slash); + dir = xstrndup (fullpath, slash - fullpath); + base = xstrdup (++slash); + + mdir = opendir (dir); + if (mdir == NULL) { + if (quiet < 2) + error (0, errno, _("can't search directory %s"), dir); + free (dir); + free (base); + return NULL; + } + + while ((manlist = readdir (mdir))) { + if (manlist->d_ino == inode && + strcmp (base, manlist->d_name) > 0) { + free (base); + base = xstrdup (manlist->d_name); + debug ("ult_hardlink: (%s)\n", base); + } + } + closedir (mdir); + + /* If we already are the link with the smallest name value */ + /* return NULL */ + + if (strcmp (base, slash) == 0) { + free (dir); + free (base); + return NULL; + } + + ret = xasprintf ("%s/%s", dir, base); + free (dir); + free (base); + return ret; +} + +/* Resolve all symbolic links within 'fullpath'. + * Returns a newly allocated string. + */ +static char *ult_softlink (const char *fullpath) +{ + char *resolved_path; + + resolved_path = canonicalize_file_name (fullpath); + if (!resolved_path) { + /* discard the unresolved path */ + gripe_canonicalize_failed (fullpath); + return NULL; + } + + debug ("ult_softlink: (%s)\n", resolved_path); + + return resolved_path; +} + +static char *find_include_directive (char *path) +{ + decompress *decomp; + const char *buffer; + char *directive; + + decomp = decompress_open (path, DECOMPRESS_ALLOW_INPROCESS); + if (!decomp) { + if (quiet < 2) + error (0, errno, _("can't open %s"), path); + return NULL; + } + decompress_start (decomp); + + /* make sure that we skip over any comments */ + do { + buffer = decompress_readline (decomp); + } while (buffer && STRNEQ (buffer, ".\\\"", 3)); + + directive = xstrdup (buffer ? buffer : ""); + + decompress_wait (decomp); + decompress_free (decomp); + + return directive; +} + +/* Test 'buffer' to see if it contains a .so include. If so and it's not an + * absolute filename, return newly allocated string whose contents are the + * include. + */ +static char *test_for_include (const char *buffer) +{ + if (!buffer) + return NULL; + + /* strip out any leading whitespace (if any) */ + while (CTYPE (isspace, *buffer)) + buffer++; + + /* see if the `command' is a .so */ + if (strncmp (buffer, ".so", 3) == 0) { + buffer += 3; + + /* strip out any whitespace between the command and + its argument */ + while (CTYPE (isspace, *buffer)) + buffer++; + + /* If .so's argument is an absolute filename, it could be + * either (i) a macro inclusion, (ii) a non local manual page + * or (iii) a (somewhat bogus) reference to a local manual + * page. + * + * If (i) or (ii), we must not follow the reference. (iii) is + * a problem with the manual page, thus we don't want to + * follow any absolute inclusions in our quest for the + * ultimate source file */ + if (*buffer != '/') { + const char *end = buffer; + while (*end && !CTYPE (isspace, *end)) + ++end; + return xstrndup (buffer, end - buffer); + } + } + return NULL; +} + +static char *find_include (const char *name, const char *path, + const char *include) +{ + char *target; + struct compression *comp; + + /* Restore the original path from before ult_softlink() etc., in + * case it went outside the mantree. + */ + target = xasprintf ("%s/%s", path, include); + assert (target); + + /* If the original path from above doesn't exist, try to create new + * path as if the "include" was relative to the current man page. + */ + if (!CAN_ACCESS (target, F_OK)) { + comp = comp_file (target); + free (target); + if (comp) { + target = comp->stem; + comp->stem = NULL; /* steal memory */ + } else + target = NULL; + } + + if (!target) { + char *dirname = dir_name (name); + char *temp_file = xasprintf ("%s/%s", dirname, include); + assert (temp_file); + free (dirname); + + if (CAN_ACCESS (temp_file, F_OK)) + /* Just plain include. */ + target = xstrdup (temp_file); + else { + comp = comp_file (temp_file); + if (comp) { + target = comp->stem; + comp->stem = NULL; /* steal memory */ + } + } + free (temp_file); + } + + if (target) { + char *canonicalized = canonicalize_file_name (target); + if (canonicalized) + return canonicalized; + else { + gripe_canonicalize_failed (target); + free (target); + return NULL; + } + } else { + if (quiet < 2) + error (0, 0, _("can't resolve %s"), include); + return NULL; + } +} + +struct ult_key { + char *name; + int flags; +}; + +static struct ult_key *ult_key_new (const char *name, int flags) +{ + struct ult_key *ukey = XMALLOC (struct ult_key); + ukey->name = xstrdup (name); + ukey->flags = flags; + return ukey; +} + +static bool ATTRIBUTE_PURE ult_key_equals (const void *key1, const void *key2) +{ + struct ult_key *ukey1 = (struct ult_key *) key1; + struct ult_key *ukey2 = (struct ult_key *) key2; + return ukey1->flags == ukey2->flags && + STREQ (ukey1->name, ukey2->name); +} + +static size_t ATTRIBUTE_PURE ult_key_hash (const void *key) +{ + struct ult_key *ukey = (struct ult_key *) key; + return string_hash (ukey->name) ^ (size_t) ukey->flags; +} + +static void ult_key_free (const void *key) +{ + struct ult_key *ukey = (struct ult_key *) key; + free (ukey->name); + free (ukey); +} + +static struct ult_value *ult_value_new (void) +{ + struct ult_value *uvalue = XMALLOC (struct ult_value); + uvalue->path = NULL; + uvalue->trace = new_string_list (GL_ARRAY_LIST, true); + return uvalue; +} + +static void ult_value_free (const void *value) +{ + struct ult_value *uvalue = (struct ult_value *) value; + if (uvalue) { + free (uvalue->path); + gl_list_free (uvalue->trace); + free (uvalue); + } +} + +gl_map_t ult_cache = NULL; + +/* + * Find the ultimate source file by following any ".so filename" directives + * in the first line of the man pages. Also (optionally) trace symlinks and + * hard links(!). + * + * name is full pathname, path is the MANPATH directory (/usr/man) + * flags is a combination of SO_LINK | SOFT_LINK | HARD_LINK + */ +const struct ult_value *ult_src (const char *name, const char *path, + struct stat *buf, int flags) +{ + char *base = xstrdup (name); + struct ult_key *key; + const struct ult_value *existing; + struct ult_value *value; + struct stat new_buf; + + if (!ult_cache) + ult_cache = gl_map_create_empty (GL_HASH_MAP, + ult_key_equals, ult_key_hash, + ult_key_free, ult_value_free); + key = ult_key_new (name, flags); + if (gl_map_search (ult_cache, key, (const void **) &existing)) { + ult_key_free (key); + return existing; + } + value = ult_value_new (); + + debug ("ult_src: File %s in mantree %s\n", name, path); + + gl_list_add_last (value->trace, xstrdup (name)); + + /* as ult_softlink() & ult_hardlink() do all of their respective + * resolving in one call, only need to sort them out once + */ + + /* If we don't have a buf, allocate and assign one */ + if (!buf && ((flags & SOFT_LINK) || (flags & HARD_LINK))) { + buf = &new_buf; + if (lstat (base, buf) == -1) { + if (quiet < 2) + error (0, errno, _("can't resolve %s"), base); + goto err; + } + } + + /* Permit semi local (inter-tree) soft links */ + if (flags & SOFT_LINK) { + assert (buf); /* initialised above */ + if (S_ISLNK (buf->st_mode)) { + /* Is a symlink, resolve it. */ + char *softlink = ult_softlink (base); + if (softlink) { + free (base); + base = softlink; + } else + goto err; + } + } + + /* Only deal with local (inter-dir) HARD links */ + if (flags & HARD_LINK) { + assert (buf); /* initialised above */ + if (buf->st_nlink > 1) { + /* Has HARD links, find least value */ + char *hardlink = ult_hardlink (base, + buf->st_ino); + if (hardlink) { + free (base); + base = hardlink; + } + } + } + + if (flags & SO_LINK) { + int i; + for (i = 0; i < 10; ++i) { + char *directive, *include; + + directive = find_include_directive (base); + if (!directive) + goto err; + + include = test_for_include (directive); + free (directive); + if (!include) + break; + + free (base); + base = find_include (name, path, include); + free (include); + if (!base) + goto err; + + debug ("ult_src: points to %s\n", base); + + gl_list_add_last (value->trace, xstrdup (base)); + } + if (i == 10) { + if (quiet < 2) + error (0, 0, _("%s is self referencing"), + name); + goto err; + } + } + + /* We have the ultimate source */ + value->path = xstrdup (base); + gl_list_add_last (value->trace, xstrdup (base)); + gl_map_put (ult_cache, key, value); + free (base); + return value; + +err: + /* The cache is short-lived and only within a single process, so + * negative caching is fine. + */ + ult_value_free (value); + gl_map_put (ult_cache, key, NULL); + free (base); + return NULL; +} -- cgit v1.2.3